blower motor for heater when works only works in next to highest setting on 2002 Chevrolet Malibu

when the blower works it dont work all the time either what is the easiest way to check whats wrong with it

Asked by for the 2002 Chevrolet Malibu
poss blower motor resistor is bad
ok easiest way to check that ?
ck ohms on all cycles, there should be a diff on each level
ok thanks i will try that